package com.itheima_06;

import java.util.ArrayList;
import java.util.Scanner;

public class StudentManager {
    public static void main(String[] args) {
        ArrayList<Student> students = new ArrayList<>();

        while (true) {
            System.out.println("-----欢迎来到学生管理系统-----");
            System.out.println("1 添加学生");
            System.out.println("2 删除学生");
            System.out.println("3 修改学生");
            System.out.println("4 查看所有学生");
            System.out.println("5 退出");
            System.out.println("请输入你的选择：");

            Scanner sc = new Scanner(System.in);
            String line = sc.nextLine();

            switch (line) {
                case "1":
                    addStudent(students);
                    break;
                case "2":
                    deleteStudent(students);
                    break;
                case "3":
                    updateStudent(students);
                    break;
                case "4":
                    findAllStudent(students);
                    break;
                case "5":
                    System.out.println("谢谢使用");
                    System.exit(0);
            }
        }
    }

    // 添加学生信息
    public static void addStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);
        String sid = "";

        while (true) {
            System.out.println("请输入学生学号：");
            sid = sc.nextLine();

            boolean flag = isUsed(array, sid);
            if (flag) {
                System.out.println("你输入的学号已经被使用，请重新输入");
            } else {
                break;
            }
        }

        System.out.println("请输入学生姓名");
        String name = sc.nextLine();

        System.out.println("请输入学生年龄：");
        String age = sc.nextLine();

        System.out.println("请输入学生地址：");
        String address = sc.nextLine();

        Student s = new Student(sid, name, age, address);
        array.add(s);
        System.out.println(array.size());
    }

    // 判断学号是否被使用
    public static boolean isUsed(ArrayList<Student> array, String sid) {
        boolean flag = false;
        for (int i = 0; i < array.size(); i++) {
            Student s = array.get(i);
            if (s.getSid().equals(sid)) {
                flag = true;
                break;
            }
        }
        return flag;
    }

    // 查看学生信息
    public static void findAllStudent(ArrayList<Student> array) {
        if (array.size() == 0) {
            System.out.println("无信息，请先添加信息再查询");
        } else {
            System.out.println("学生\t\t\t姓名\t\t年龄\t\t居住地");
            for (int i = 0; i < array.size(); i++) {
                Student s = array.get(i);
                System.out.println(s.getSid() + "\t\t\t" + s.getName() + "\t\t" + s.getAge() + "\t\t" + s.getAddress());
            }
        }
    }

    // 删除学生信息
    public static void deleteStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);

        System.out.println("请输入你要删除的学生的学号：");
        String sid = sc.nextLine();
        int index = -1;

        for (int i = 0; i < array.size(); i++) {
            Student s = array.get(i);
            if (s.getSid().equals(sid)) {
                array.remove(i);
                index = i;
                break;
            }
        }

        if (index == -1) {
            System.out.println("该信息不存在，请重新输入");
        } else {
            System.out.println("删除成功");
        }
    }

    // 修改学生信息
    public static void updateStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);

        System.out.println("请输入你要修改的学生的学号：");
        String sid = sc.nextLine();
        System.out.println("请输入学生新姓名：");
        String name = sc.nextLine();
        System.out.println("请输入学生新年龄：");
        String age = sc.nextLine();
        System.out.println("请输入学生新居住地：");
        String address = sc.nextLine();

        for (int i = 0; i < array.size(); i++) {
            Student s = array.get(i);
            if (s.getSid().equals(sid)) {
                s.setName(name);
                s.setAge(age);
                s.setAddress(address);
            }
        }
    }

}
